For the Time Bomb, it's better to change it I think, since it's too messy. For death mark, actually ALL the abilities that were boosting health didn't work even before (the health boost remained unchanged!! )

OK I think the health boost issues should be fixed. For the Time Bomb instead I think it's too bugged, I had that crash too and I can't figure it out why happens
edit: maybe now works, had to tell the ability to check the target card is alive (otherwise would try to kill / remove twice a card that was already killed!)